Radiation-sensitive composition, planographic printing plate precursor, and plate-making method for planographic printing plate

Patent metadata

Field	Value
Publication number	US-2019329545-A1
Application number	US-201916409856-A
Country	US
Kind code	A1
Filing date	May 12, 2019
Priority date	Nov 16, 2016
Publication date	Oct 31, 2019
Grant date	—

Abstract

A planographic printing plate precursor includes: a support; and an image recording layer which includes a radical initiator, a radical polymerizable component, and a radiation absorption compound, and in which the image recording layer shows two or more peaks of a radical generation amount in a radical generation amount-versus-time curve after exposure to image forming radiation, in which the radical initiator includes an electron-donating radical initiator and an electron-accepting radical initiator, and the radiation absorption compound comprises a compound represented by the following Formula 1.

First claim

What is claimed is:

1 . A planographic printing plate precursor, comprising:
a support; and an image recording layer which comprises a radical initiator, a radical polymerizable component, and a radiation absorption compound, and wherein the image recording layer shows two or more peaks of a radical generation amount in a radical generation amount-versus-time curve after exposure to image forming radiation, wherein the radical initiator comprises an electron-donating radical initiator and an electron-accepting radical initiator, and wherein the radiation absorption compound comprises a compound represented by the following Formula 1:

wherein, in Formula 1, R 1 represents a group capable of cleaving R 1 —X bond due to exposure to image forming radiation, X represents —S— or —NR N —, R N represents a hydrocarbon group, R 2 and R 3 each independently represent a hydrogen atom or an alkyl group, R 2 and R 3 may be linked to each other to form a ring, Ar 1 and Ar 2 each independently represent a group forming a benzene ring or a group forming a naphthalene ring, Y 1 and Y 2 each independently represent an oxygen atom, a sulfur atom, —NR 0 —, or a dialkylmethylene group, R 4 and R 5 each independently represent an alkyl group, R 6 to R 9 each independently represent a hydrogen atom or an alkyl group, R 0 represents a hydrogen atom, an alkyl group, or an aryl group, and Za represents a counter ion that neutralizes the charge.

2 . The planographic printing plate precursor according to claim 1 , wherein X in Formula 1 represents —S—.

3 . The planographic printing plate precursor according to claim 1 , wherein the radiation absorption compound is a decomposition type radiation absorption compound.

4 . The planographic printing plate precursor according to claim 1 , wherein the electron-donating radical initiator comprises a borate compound.

5 . The planographic printing plate precursor according to claim 4 , wherein the borate compound has one or more aryl groups having an electron-withdrawing group.

6 . The planographic printing plate precursor according to claim 1 , wherein electron-accepting radical initiator comprises an iodonium salt.

7 . The planographic printing plate precursor according to claim 6 , wherein the iodonium salt has an electron-donating group as a substituent.

8 . The planographic printing plate precursor according to claim 1 ,
wherein a peak interval between a peak of the radical generation amount which is initially generated with respect to time after the exposure to the image forming radiation and at least one of peaks of the radical generation amount which are generated subsequent to the initially generated peak, among the peaks of the radical generation amount, is 40 ms or greater.

9 . The planographic printing plate precursor according to claim 1 ,
wherein a difference between a highest occupied molecular orbital of the electron-donating radical initiator and a highest occupied molecular orbital of the radiation absorption compound is 0.61 eV or greater.

10 . The planographic printing plate precursor according to claim 1 ,
wherein a difference between a lowest unoccupied molecular orbital of the electron-accepting radical initiator and a lowest unoccupied molecular orbital of the radiation absorption compound is 0.90 eV or less.

11 . The planographic printing plate precursor according to claim 1 ,
wherein the image recording layer is removable by at least one selected from the group consisting of dampening water and printing ink.

12 . A plate-making method for a planographic printing plate, the method comprising:
subjecting the planographic printing plate precursor according to claim 1 to image-wise light exposure; and removing a non-image area of an image recording layer from the exposed planographic printing plate precursor in the presence of a developer having a pH of 2 to 14.

13 . A plate-making method for a planographic printing plate, the method comprising:
subjecting the planographic printing plate precursor according to claim 1 to image-wise light exposure; and supplying at least one selected from the group consisting of printing ink and dampening water on a printing press to remove a non-image area of an image recording layer.

Assignees

• Fujifilm Corp

Inventors

• Shibamoto Tadao
• Murakami Taira
• Tsumura Kyosuke
• Kudo Kotaro

Classifications

• G03F7/0388

  with ethylenic or acetylenic bands in the side chains of the photopolymer · CPC title

• G03F7/033

  the binders being polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. vinyl polymers · CPC title

• G03F7/027

  Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds (G03F7/075 takes precedence) · CPC title

• C08F2/48

  by ultraviolet or visible light · CPC title

• B41C2210/06

  Developable by an alkaline solution · CPC title